const createError = require('http-errors')
const express = require('express')
const path = require('path')
const cookieParser = require('cookie-parser')
const logger = require('morgan')
const cors = require('cors')
//路由模块(中间件)
const usersRouter = require('./routes/users')

/**
 * 创建express应用
 */
const app = express()

// 设置使用jade模板引擎
app.set('views', path.join(__dirname, 'views'))
app.set('view engine', 'jade')

/**
 * 中间件，有先后顺序
 */
app.use(logger('dev'))
app.use(express.json())
app.use(express.urlencoded({ extended: false }))
app.use(cookieParser())
//静态资源(位于public目录下)
app.use(express.static(path.join(__dirname, 'public')))

//使用路由中间件
//当访问users文件时，具体操作在usersrouter中
app.use('/api/v1/users', usersRouter)

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404))
})

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message
  res.locals.error = req.app.get('env') === 'development' ? err : {}

  // render the error page
  res.status(err.status || 500)
  res.render('error')
})

module.exports = app
